Laminated porous film, separator for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery

Abstract

An object of the present invention is to provide a laminated porous film excellent in handling ability. A laminated porous film having a layer containing a polymer other than a polyolefin laminated on at least one surface of a polyolefin porous film, wherein the uplift quantity of a side perpendicular to the machine direction, when allowed to stand still for 1 hour under an environment of a temperature of 23° C. and a humidity of 50%, is 15 mm or less.

What is claimed is: 
     
         1 . A method for producing a laminated porous film having a layer containing a polymer other than a polyolefin laminated on at least one surface of a polyolefin porous film, the laminated porous film being obtained by applying a coating fluid containing a polymer other than a polyolefin and a medium onto at least one surface of a polyolefin porous film, and drying the coating fluid at given drying temperature when imparted to the polyolefin porous film under the same temperature environment as the drying temperature, elongation rate thereof is 1% or less. 
     
     
         2 . A method for producing a laminated porous film according to  claim 1 , wherein the drying temperature is 30 to 80° C. 
     
     
         3 . A method for producing a laminated porous film according to  claim 1 , wherein 80 wt % or more of the medium is composed of water. 
     
     
         4 . A method for producing a laminated porous film according to  claim 1 , wherein drying the coating fluid at given drying temperature while imparting film tension of 0.05 N or more per 1 mm of the film width.